Open topic with navigation

Nikon A / Sanyo Denki Serial Absolute Encoders

This section provides wiring instructions for a motor equipped with a Nikon A 2.5Mhz, a Nikon A 4Mhz, or a Sanyo Denki PA035C 2.5Mhz serial absolute encoder. These encoders transmit their position data using a specialized serial bit stream protocol via a RS-485 pair rather than A-B incremental quadrature pulses. When these encoders are provided with a battery backup source, they function as a high resolution absolute encoder that returns 17-bits of resolution per revolution and a 16-bit "turns count" battery backed-up register for a total of 33-bits of encoder position information.

Due to the additional capabilities needed to process the absolute encoder signal, these encoders may require the "Enhanced" versions of the Guidance Controllers. Please contact Brooks for the current hardware requirements for interfacing to these types of encoders.

For information on configuring this type of encoder, please see the Software Setup section of the Controller Software section of the PreciseFlex Library.

In addition to reviewing the information in Table 19-3, also review the Installation Information for important recommendations on the use of twisted pair wires and shield grounding.

For the multi-turn counter to operate properly, a battery must be connected to the Absolute Encoder Battery Connector on the MCIM/MIDS3 board. Please see the information on that connector for detailed pin outs and plug types. Table 19-4 contains information on the required battery power.

NOTE: Please be aware that if the external battery is disconnected while the controller's power is off or the cable from the controller to the encoder is disconnected at anytime, the multi-turn data may be lost and the absolute position of the motor and encoder will have to be reestablished.